The present invention relates generally to a method and apparatus for creating a decorative textured or antiqued surface on the outer face of cured concrete blocks, and more specifically to such a method and system wherein such a decorative surface is created upon respective block surfaces, some of which blocks may have previously been split to create a randomly textured surface. The method and apparatus of the present invention modifies the textured surface so as to create a textured or antique-appearing surface while at the same time preserving the structural integrity of the remaining surfaces and bulk composition of the block. The finished textured blocks treated in accordance with the present invention are desirable for use in landscaping applications for block walls of substantial height, or in various architectural block applications.
In the past, various techniques and systems have been proposed for treatment of concrete blocks in order to create a textured or antique appearance. These techniques include exposure of the block to milling or tumbling operations which have been effected in facilitating and creating such an appearance. Such techniques, while effective, tend to be time consuming and may require additional steps and/or operations in the handling of the blocks prior to such exposure. Additionally, when certain tumbling operations are undertaken, the bulk structure or body of the blocks may be compromised due to exposure to undesirable mechanical forces including shock forces and the like. The method and system of the present invention confines shock exposure to the localized surface being treated, thereby protecting and preserving the structural integrity of the blocks.
Blocks in accordance with the present invention are prepared in accordance with U.S. Pat. Nos. 5,484,263 and 5,623,797, each of which is assigned to the Assignee of the present invention. These blocks are typically prepared with a textured surface resulting from a splitting of a dual block blank along a certain central line to form two blocks with outer surfaces. While these textured surfaces are attractive and useful for a wide variety of applications, the present invention expands the application of these blocks to those arrangements wherein a textured or antique appearance is desired. The block treatment system of the present invention is adapted for use in combination with block conveyors, thereby enabling the process to be undertaken on an in-line basis, without adding or requiring additional handling and/or operational system modifications which would either add or require intermediate stacking and/or curing steps. Thereby such an in-line process renders the system expeditious and efficient, and results in a block appearance which has a desired application in commerce.
Therefore, it is a primary object of the present invention to provide an improved method and apparatus for creating a decorative textured or antiqued surface on an outer face of cured concrete blocks, wherein the textured or antiqued surface is created without compromising or adversely affecting the structural integrity of the block.
A further object of the present invention is to provide an improved system for exposing a concrete block to repeated impact from a plurality of rotating texturing elements, whereby a surface of the block takes on an textured or antiqued appearance, with this appearance being created without adversely affecting the planar surface characteristics of the remaining surfaces of the block.
It is a still further object of the present invention to provide an improved system and apparatus for creating a textured or antiqued surface on concrete blocks, with the system including a block supporting conveyor having an axis of motion for transporting the blocks through a treatment zone in which a plurality of rotary texturing elements are applied to the blocks, wherein the system grippingly engages said blocks while moving the rotating elements along an axis which is parallel to the respective surface to be textured, and with the rotating elements making repeated contact with the block surface for creating a textured or antiqued appearance.
Other and further objects of the present invention will become apparent to those skilled in the art upon a study of the following specification, appended claims, and accompanying drawings.
In accordance with the present invention, a decorative textured or antiqued surface is created on an outer face of cured concrete blocks by undertaking the steps of initially positioning the blocks to be treated within a treatment zone. While passing through the treatment zone, the blocks exposed to a plurality of texturing elements. Such texturing elements are generally in the form of hardened spheres, with these hardened spheres being secured to a distal end of support cables, which support cables may be flexible. Proximal ends of the cables are in turn secured to one or more support shafts mounted for rotation along a generally vertical axis adjacent to respective surfaces of the blocks to be treated. The support shaft is rotated at a rate sufficient to create a centrifugal force which positions the texturing elements radially outwardly from the shaft, and at a radial extension sufficient to cause the elements to strike the block surfaces. The rotating support shaft is, in turn, mounted within a frame which is moved along an axis parallel to the block surfaces being treated. The centrifugal force generated by rotation or orbital motion of the texturing elements causes the texturing elements to repeatedly impact. respective block surfaces so as to create the forces necessary to texture and/or antique the selected surfaces. Following this operation, the treated blocks are then moved along the support surface, generally a conveyor, to a pallet loading station.